Since lithos means "stone" in Greek, the name Paleolithic was given to the older part of the Stone Age. The first known period of human culture, the Paleolithic actually covers almost all of human history, from the first use of stone tools around 2.5 million years ago until the invention of agriculture around 10,000 years ago. For almost all that time, humans used the very crudest of stone tools, produced by chipping away flakes of stone in order to make an edge for an ax or knife. Near the end of the period, animal bones and antlers were being used for tools, especially pointed tools, and sculpted figures and cave art were being produced. The Paleolithic gave way to the Mesolithic ("Middle Stone Age") period, with its tools made of polished stone, wood, and bone.